Day/Night Cycle Issues

[ponponz]

Okay, so I'm making a flash site that's supposed to have a day/night cycle that works in real time

Right now, the plan is to have a ten frame animation play once and stop after it reached the end of the movieclip timeline when the clock hits a certain time and a movie is loaded


The problem is that whenever try testing the animation, it loops. I believe the problem is that a duplicate of the movieclip keeps attaching itself in the original's place

stop();

var updateTime = setInterval(currenttime, 1000);
function currenttime() {
    var today = new Date();
    var minutes = today.getMinutes();
    var hours = today.getHours();
    trace(today);
    trace(minutes);
    trace(hours);
    var DAWN = hours == 5 && minutes == 00;
    var DAY = hours == 20 && minutes == 15;
    if (DAWN<today) {
        attachMovie("TownEarly", "TownEarly", 10);
        unloadMovie(TownDay);
        trace("It is dawn");
    }
    if (DAWN<DAY) {
        attachMovie("TownDay", "TownDay", 10);
        unloadMovie(TownEarly);
        trace("It is day");
    }
} 

Is there a way to check if a movieclip is already attached and then prevent a duplicate from taking it's place